By Deborah Jackson, editor National Liquor News

As many grape growers feel the pinch of dropping grape prices, researchers are looking at innovative ways to turn a profit from grape waste leftover in the winemaking process.

Wineries in the Murray-Darling/Swan Hill Wine region last week revealed average prices for red grape varieties had dropped to the lowest amount in a decade. 

National figures will be released in the Winemakers’ Federation of Australia’s National Vintage Report on 17 July.

Grape marc is the solid waste, including skins, stalks and seeds, leftover after crushing the juice from grapes.

Researchers from the University of Adelaide, say improving the processing of grape marc can generate revenue from recovered alcohol through further processing and distillation for use in spirits such as brandy and for fortifying wines.

University of Adelaide researcher, Dr Ravichandra Potumarthi, estimates several hundred thousand tonnes of red and white grape marc is produced each year.

“It’s around 15 to 30 per cent of the weight of the grapes used for winemaking and disposal poses a problem for the industry.

“Our research is aimed at developing sustainable technology and processes that will help the wine industry generate more revenue and make better use of this byproduct.”

Dr Potumarthi is working with wine science senior lecturer Dr David Jeffery and industry partners to investigate alternate fermentation methods, process optimisation and pre-treatment techniques. 

He is also undertaking a cost benefit analysis of the processes involved, and assessing how alcohol yield and quality can be improved.

“I’m looking to see how to produce more alcohol from the same amount of grape marc through more efficient processes, and also developing new ones.

“If we can enhance processing efficiencies for alcohol production, producers will be able to generate more revenue from the same amount of grapes; converting a waste stream into a valued product.

“In this way the wine industry will be able to address environmental concerns of waste disposal and make their industry more sustainable.”

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The Shout Team

The leading online news service for Australia's beer, wine, spirits and hospitality industries.

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